LEt's PLay "Name that Pipe"

What the hell is this pipe sticking out of the ground for? It used to have an empty electrical outlet screwed on top of it which I removed. There are no wires or anything going into or out of this thing. Yet I can't pull it out of the ground because it won't budge. Does this serve some kind of purpose or can I just pull/dig it out?

Well it has always been un-capped and exposed. I cut it down and then stuffed a long rag down the top and then buried it.

A proper cap may be purchased at any hardware store. A little glue and you would be safe.
However, now that the pipe opening is below ground level its conceivable that the rag would rot away and that you would have a river of water running into your electrical panel.
If this happened, you would then have a major problem on your hands.

See if you can force air down it....if it flows....it's comeing out somewhere....if not...then the other end is blocked...

too late, already found a nice cap at Lowes. Cut it down, put some water-proof silicone inside the cap and placed it over the hole than buried it. I'm sure it was an electrical conduit that was not in use because as I said, it had a box on top without any outlets wired in. Just an empty box sitting screwed into the top.